Ventilation

• Although building codes in some localities do not require crawl space ventilation, the lack of proper air movement in an enclosed area such as a crawl space will lead to moisture problems. This in turn will result in mold growth eventually. Vents should be installed whenever possible if not included in the original construction. This involves purchasing crawl space vents from home supply vendors, including special panels made exclusively for manufactured homes.
  
  

Mechanical Ventilation Procedures

• Fans are also used to introduce a flow of air into the crawl space, and to exhaust humid air. This allows for a degree of control over moisture, and complements the existing ventilation. In some cases, an overly-moist condition in a crawl space requires closing off of crawl space vents and completely controlling the environment with fans specifically designed for this purpose.
  
  

Moisture Reduction

• Moisture is a constant concern in a crawl space. Although a certain amount of moisture will generally be present, excessive moisture from plumbing leaks, dryer vents, and air-conditioner condensation leads to mold growth in a crawl space. These problems must be corrected by mechanical approaches such as replacing or repairing faulty plumbing lines, re-routing dryer vents to the exterior of the foundation, and installing collection tubes to catch the condensation from HVAC units and routing these tubes to the exterior of the building. A plastic vapor diffusion barrier of at least 6 mil in thickness should be installed over at least 70 percent of the soil in the crawl space.
  
  

Chemical Mold Treatment

• Borates are a derivative of the mineral boron. This element has natural bacteria-killing properties, and the borates derived from boron such as (boric acid) are effective in treating mold. Commercially-available paints containing borates should be used on exposed wood in a crawl space. Many wood preservatives contain borates and are effective when applied to sub-flooring and support piers in a crawl space. Fungicides that are registered with the EPA may also be applied.
  
  

Other Chemical Treatments

• One common chemical that is used for mold treatment is bleach. The EPA recommends the use of mild detergent and water mixtures in their guidelines for mold remediation. Hydrogen peroxide is another household product that produces positive results in mold treatment, and any of these chemicals are useful for a crawl space mold treatment.